1. Field of the Invention
The present invention relates to a transfer device and an image forming apparatus.
2. Description of the Related Art
For example, there are known electrophotographic image forming apparatuses in which a secondary transfer unit is attached to a cover of a main body to allow easy handling of a paper jam occurring between a secondary transfer roller and an opposed roller or neighboring parts thereof (see Japanese Patent Application Laid-open No. 2006-259449, Japanese Patent Application Laid-open No. 2009-139436, and Japanese Patent Application Laid-open No. 2011-85867). In this case, when the cover is opened, the secondary transfer roller can be separated from the opposed roller, thereby to facilitate removal of jammed paper.
In some of image forming apparatuses having a secondary transfer unit attached to a cover as described above, the secondary transfer unit is configured to be easy for a user or the like to replace for further improved maintenance properties.
However, on replacement of the secondary transfer unit, when the cover is closed while the secondary transfer unit is imperfectly attached to the cover, the secondary transfer roller may not be correctly positioned, thereby exerting influence on image formation and the like after the replacement. In addition, when the secondary transfer unit is not correctly positioned at closing of the cover, the components may be broken.
The problem of improper attachment of the unit to the cover may also arise in units other than the secondary transfer unit.
Accordingly, in light of the foregoing circumstances, there is needed to provide an image forming apparatus that allows suppression of occurrence of improper attachment of the unit.